661325764220 has 48 divisors (see below), whose sum is σ = 1515605769216. Its totient is φ = 240391848000.

The previous prime is 661325764217. The next prime is 661325764247. The reversal of 661325764220 is 22467523166.

It is a Smith number, since the sum of its digits (44) coincides with the sum of the digits of its prime factors.

It is a Harshad number since it is a multiple of its sum of digits (44).

It is a congruent number.

It is an unprimeable number.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 24905 + ... + 1150335.

It is an arithmetic number, because the mean of its divisors is an integer number (31575120192).

Almost surely, 2^661325764220 is an apocalyptic number.

It is an amenable number.

661325764220 is an abundant number, since it is smaller than the sum of its proper divisors (854280004996).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

661325764220 is a wasteful number, since it uses less digits than its factorization.

661325764220 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 1128122 (or 1128120 counting only the distinct ones).

The product of its (nonzero) digits is 725760, while the sum is 44.

The spelling of 661325764220 in words is "six hundred sixty-one billion, three hundred twenty-five million, seven hundred sixty-four thousand, two hundred twenty".